1. Field of the Disclosure
The present disclosure relates generally to wireless communication, and more particularly to a system and method for optimization of power consumption in a dual subscriber identity module (SIM) mobile phone, where both SIMs are in fully connected mode or semi connected mode and use a single radio resource control (RRC) connection when both SIMs have registered on the same public land mobile network (PLMN) and listen on a same cell of the same PLMN.
2. Description of the Related Art
Wireless communication systems have developed through various generations, including a first-generation (1G) analog wireless phone service, a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and third-generation (3G) and fourth-generation (4G) high speed data/Internet-capable wireless services. Currently, wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3rd generation partnership project (3GPP) Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Currently, the market is mainly driven by users who want to switch between carriers to take advantage of the best deals. Business and professional users could use these phones to have a separate mobile number for personal and official calls. A large number of buyers of dual SIM mobile phones use the two SIMs on the mobile phone to switch between network providers if coverage gets patchy. In addition, people who are travelling from one state to other state usually use dual SIM mobile phones in order to get the services of the new state's local network provider.
FIG. 1 is a schematic of a dual SIM dual standby (DSDS) mobile phone and a dual SIM dual active (DSDA) mobile phone in connected mode. The dual SIM mobile phones are popularly classified into two categories:
(i) DSDS, in which only one radio frequency (RF) Transceiver is present; and
(ii) DSDA, in which two transceivers are present.
FIG. 2 is a schematic of security mode procedures. The dual SIM mobile phones where both SIMs have separate ciphering and integrity keys. The first SIM signaling is with the first SIM's circuit switched (CS) or packet switched (PS) ciphering and integrity keys and the second SIM signaling is with the second SIM's CS or PS ciphering and integrity keys.
The challenges that are faced by the dual SIM mobile phones in connected mode when camped on the same cell of the PLMN are as follows.
Among DSDS mobile phones in connected mode, when either one of the SIMs enters or remains in CS connected mode, then the other SIM which is in idle mode will not be able to receive paging for mobile terminated (MT) calls. In this case, both SIMs cannot remain in connected mode.
Among DSDA mobile phones in connected mode, the two transceivers present on the mobile phones are switched on for the complete duration, which increases the consumption of power. In addition, since both SIMs are camped on the same cell of a PLMN, most of the RRC procedures are duplicated.
Accordingly there is a need to provide a method and system for optimizing power consumption in dual SIM mobile phones, when both SIMs are camped and registered on the same cell of a PLMN.